The hip joint functions as one of the most important joints in the human body. Designed for both mobility and stability, the hip allows the entire lower extremity to move in three planes of motion, while providing an important shock absorption function to the torso and upper body. view

Hip fractures are breaks in the upper part of the thigh bone (femur) and are the second-most common break in the human body after wrist fractures under the age of 75 years and the most common fracture after 75 years of age. view

A hip dislocation is classified according to the direction of the dislocation (anterior, posterior, superior, inferior), the amount of force it took to dislocate the hip, whether it is accompanied by a fracture (fracture/dislocation), and whether or not the patient has had a previous hip replacement on the affected side. view

Compartment syndrome is an orthopedic emergency. Thigh compartment syndrome occurs when the pressure in the front, back, or inner thigh compartments rises above the blood pressure needed for the heart to pump blood to the thigh. view

A hip/thigh strain, by definition, is an injury to a muscle or muscles around the hip and thigh. These injuries can be caused by one specific injury, such as a fall or while playing sports, or by repetitive micro-trauma over time, often referred to as overuse injuries. view

HIP DISLOCATION

Pathology

A hip dislocation is classified according to the direction of the dislocation (anterior, posterior, superior, inferior), the amount of force it took to dislocate the hip, whether it is accompanied by a fracture (fracture/dislocation), and whether or not the patient has had a previous hip replacement on the affected side.

When younger patients sustain a hip dislocation, there has usually not been a previous hip replacement, and it is usually a posterior hip dislocation (out the back) caused by significant force, that results in a fracture of the hip socket (acetabulum). The fractured socket then prevents the hip bone (femoral head) from staying within the hip joint once it is put back. X-rays show the direction of the dislocation and if there is an associated fracture of the hip bone (femur) or socket (acetabulum). A physical examination is important to check for injuries to other structures, such as muscles or nerves.

When older patients sustain a hip dislocation, there usually has been a previous hip replacement on the affected side. These dislocations can be in any direction and may be caused by trauma, such as a fall, or normal daily activities, such as getting out of a chair or car. Dislocations caused by normal activities or when the hip has dislocated numerous times usually indicate that the hip replacement components are not in the proper position. X-rays show the direction of the dislocation, the approximate position of the hip replacement components, and whether there has been a fracture of the hip bone (femur) or socket (pelvis). When an X-ray does not provide all of the information required, a CT scan may be necessary to find out the exact position of the hip replacement components and to better image any fractures that may be present.

Treatment

Hip dislocations are orthopedic emergencies. If there has not been a fracture that prevents the hip from being put back in place (reduced), the hip needs to be reduced immediately to prevent further injury. If a fracture of the hip socket (acetabulum) has occurred that prevents the hip from being reduced, a temporary pin hooked up to traction may need to be placed in the thigh bone or leg bone to keep the hip in place. The fractured socket then needs to be fixed with plates and screws to keep the hip in place. If the thigh bone (femoral head or neck) has been fractured as well, it will need to be fixed with either pins or a metal rod or replaced if deemed unlikely ot heal by those techniques.

When there has been a hip replacement, the hip needs to be back in place as soon as possible. If this is the first dislocation, treatment may consist of a brace, careful hip precautions and therapy. If the hip is not stable after being put back in place or there have been numerous dislocations, revision hip replacement surgery to correct the position of the hip replacement components may be necessary.